The present invention relates in general to electronically operated door locks and more specifically to electrical door locks wherein a door opening code is entered through the use of a rotatable and axially moveable control knob for entering a predetermined code by contacting switches provided on a printed circuit board within the lock housing. More specifically, the present invention relates to such locks which are adaptable for replacement of ordinary dead bolt lock mechanisms in association with continued use of the door handle and spring bolt of an otherwise standard door.
Electronic door locks have been developed heretofore which provide for the manipulation of a control knob through two degrees of movement, rotation and axial translation, to select and enter individual ones of a predetermined sequence of a numerical or other bases code in association with a printed circuit board provided within the lock housing. Exemplary thereof is the electronic dial combination lock of prior application Ser. No. 06/854,330 filed Apr. 21, 1986 and now U.S. Pat. No. 4,745,784 by Klaus W. Gartner, the disclosure of which is incorporated herein by this reference. In that lock, dialing of the control knob for selection of a numerical code indicia on the dial face is translated into an electrical contact made on the circuit board within the lock housing by pushing the control knob inwardly of the lock. The circuit board has appropriate circuitry for generation of an electrical signal to an associated solenoid which controls movement of a locking lever which prevents opening of the lock until the combination was entered. The dial is rotated through a full 360.degree. of rotation allowed during entry of the code and is thereafter employed for opening the lock after the predetermined code has been entered. That lock is particularly suitable for replacing a standard gated tumbler wheel type mechanical combination lock with an electrical combination lock as more fully described in said application.